In response to questions arising from an investigation by Colorado Times Recorder, a spokesman for Immigration and Customs Enforcement (ICE) revealed last week for the first time that it detains people at its office in Centennial, located at 12445 E Caley Ave., among a cluster of buildings about 20 minutes south of Denver.

ICE Field Office in Centennial.

The location of the Denver ‘hold room,’ one of nine across the state, was previously a mystery. Its role is not identified in ICE documents, it’s not marked as a hold room or detention center on building signage, and ICE did not respond to requests from the Colorado Times Recorder and others to reveal its location and provide details about it.

Between January and October of last year, ICE held 1,398 individuals at its Denver hold room for varying lengths of time, according to data obtained by the Deportation Data Project via Freedom of Information Act request and analyzed by the Colorado Times Recorder.

Of those, 39 were children, including a one-year-old girl. 738 of the detainees, or 53%, were “Not an Aggravated Felon,” according to ICE records, and only 410 of the detainees, or just 29%, actually had a “most serious charge” listed. Many charges identified as serious were for traffic offenses, trespassing, or DUI.

ICE rules prohibit stays of over 72 hours in its hold rooms, which in Colorado are located in strip malls and office parks, but the Denver hold room, like the others in the state, held people for much longer periods.

In Denver, for example, a Nicaraguan man stayed 39 days and another man, also a Nicaraguan, stayed 36 days, according to ICE records.

Among other activities at the ICE office in Centennial, which has been the site of repeated demonstrations, immigrants are summoned there for check-ins.

Before ICE disclosed the current location of Denver’s hold room last week, ICE documents listed the Denver hold room at an address in a Montbello strip mall that now houses a furniture store.

Colorado’s other eight hold rooms are located in Alamosa at 1921 State St., in Craig at 466 Tucker St., in Colorado Springs at 415 East Pikes Peak Ave., in Durango at 32 Sheppard Drive, in Frederick at 3770 Puritan Way, in Glenwood Springs at 100 Midland Ave., in Grand Junction at 569S. Commercial Drive, and in Florence — listed as Pueblo in ICE records — at 935 State Highway 67.

In Colorado, ICE contracts with the GEO Group to run a 1,500-bed prison in Aurora. Sites for more prisons in the state are under consideration.

Democratic members of Colorado’s Congressional delegation asked ICE last week to provide detailed information about its hold rooms — and that it stop detaining people there for “extended periods.” Thirty-one members of Colorado’s state legislature made a similar demand the week before.

Read more: Secret ICE Detention Facilities Exist Around Colorado, Data Shows